Changing to HJ Non-Return Valves

RELEVANT TO: All operators without HJ SIP valves

Cylinder oil injection valves of good design, quality and condition are key to utilizing the full potential of the cylinder lubrication system.


The total lubrication system contains both
lubricators and injection valves working in
unison. Both components serve a speciĄc
purpose to ensure good cylinder lubrication and to reach a low cylinder oil consumption.
To achieve this, attention must be paid to both of these essential components.

The whole system is only as good as its
weakest part and injection valves are often overlooked when considering the lubrication


This Service Letter describes the benefits
of the HJ non-return injection valves
compared to standard non-return injection
valve. With HJ non-return injection valves
optimum design and quality is ensured.

Replacing the injection valves also ensures
new valves in optimum operating condition.
All this allows the user to get more value
from their cylinder lubrication system.

Improved performance using HJ Non-return valves


The injection valves serve to transport the cylinder oil through the liner and into the piston ring pack. In the case that the Hans Jensen Swirl Injection Principle (HJ SIP) technology is used, the oil is also distributed onto the liner wall.

The design, quality and condition of the injection valves determine the effectiveness of the valves and thereby their ability to distribute the cylinder oil satisfactory. This distribution is important to ensure a good cylinder condition and the possibility to minimise the cylinder oil consumption.

The HJ non-return injection valves do not require any machining of the cylinder liner and are ‘drop-in’ replacements to the existing valves.

The HJ non-return injection valve

There are three areas where the HJ design provides a better solution: The dead volume between the non-return valve and the nozzle, the nozzle diameter and the opening pressure.

The following paragraphs go further into details regarding these areas.